The present invention relates to an overhead conveyor system of the type that has load carrying carriages that are supported on skewed driven wheels engaging a rotatable shaft.
Overhead conveyors of the above type are represented by U.S. Pat. No. 4,203,511, issued May 20, 1980 to Uhing, U.S. Pat. No. 3,164,104, issued Jan. 5, 1965 to Hunt, and U.S. Pat. No. 3,850,280, issued Nov. 26, 1974 to Ohrnell. By reference, the disclosure of these U.S. patents is incorporated herein in their entirety as a disclosure of environments in which the present invention may be used, operating principals, and the noncarriage portion of the overhead conveyor, e.g. the drive shaft, bearings, drive motor and transmission.
This type of overhead conveyor has many advantages over less expensive overhead conveyors, such as those that employ chains, with such advantages including: cleanliness, quietness, conveying speed changes throughout the system, less maintenance, and greater flexibility in moving the carriages between individual conveyors, buffers and the like throughout the system. However, the overhead conveyor of the present invention type has a disadvantage of generally being more expensive than the chain type conveyor in initial cost, and a large part of this cost is the complexity of the carriage. The conveyor system may employ hundreds of carriages.